Trait markers, or intermediate phenotypes linking different units of analysis (self-report, performance) from the Research Domain Criteria (RDoC) matrix across populations is a necessary step in identifying at-risk individuals. In the current study, 150 healthy controls (HC) and 456 individuals with bipolar disorder (BD) Type I or II, NOS (not otherwise specified) or Schizoaffective BD completed self-report neuropsychological tests of inhibitory control (IC) and executive functioning. Bifactor analyses were used to examine the factor structure of these measures and to evaluate for invariance across groups. Bifactor analyses found modest convergence of items from neuropsychological tests and self-report measures of IC among HC and BD. The factor scores showed evidence of a general IC construct (i.e., subdomain) across measures. Importantly, invariance testing indicated that the same construct was measured equally well across groups. Groups differed on the general factor for three of the four scales. Convergence on a general IC factor and invariance across diagnosis supports the use of combined dimensional measures to identify clinical risk and highlights how prospective RDoC studies might integrate units of analysis.
Keywords: RDoC; bifactor; bipolar disorder; inhibitory control; neuropsychology.